[PATCH v9 Kernel 2/5] vfio iommu: Add ioctl defination to get dirty pages bitmap.

[Kirti Wankhede <kwankhede@nvidia.com>]

All pages pinned by vendor driver through vfio_pin_pages API should be
considered as dirty during migration. IOMMU container maintains a list of
all such pinned pages. Added an ioctl defination to get bitmap of such
pinned pages for requested IO virtual address range.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
---
 include/uapi/linux/vfio.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 35b09427ad9f..6fd3822aa610 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -902,6 +902,29 @@ struct vfio_iommu_type1_dma_unmap {
 #define VFIO_IOMMU_ENABLE	_IO(VFIO_TYPE, VFIO_BASE + 15)
 #define VFIO_IOMMU_DISABLE	_IO(VFIO_TYPE, VFIO_BASE + 16)
 
+/**
+ * VFIO_IOMMU_GET_DIRTY_BITMAP - _IOWR(VFIO_TYPE, VFIO_BASE + 17,
+ *                                     struct vfio_iommu_type1_dirty_bitmap)
+ *
+ * IOCTL to get dirty pages bitmap for IOMMU container during migration.
+ * Get dirty pages bitmap of given IO virtual addresses range using
+ * struct vfio_iommu_type1_dirty_bitmap. Caller sets argsz, which is size of
+ * struct vfio_iommu_type1_dirty_bitmap. User should allocate memory to get
+ * bitmap and should set size of allocated memory in bitmap_size field.
+ * One bit is used to represent per page consecutively starting from iova
+ * offset. Bit set indicates page at that offset from iova is dirty.
+ */
+struct vfio_iommu_type1_dirty_bitmap {
+	__u32        argsz;
+	__u32        flags;
+	__u64        iova;                      /* IO virtual address */
+	__u64        size;                      /* Size of iova range */
+	__u64        bitmap_size;               /* in bytes */
+	void __user *bitmap;                    /* one bit per page */
+};
+
+#define VFIO_IOMMU_GET_DIRTY_BITMAP             _IO(VFIO_TYPE, VFIO_BASE + 17)
+
 /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
 
 /*
-- 
2.7.0